Infrequency of BRCA2 alterations in head and neck squamous cell carcinoma.

Alterations of BRCA2 result in increased susceptibility to breast cancer in both men and women (relative lifetime risks of 0.06 and 0.8 respectively). BRCA2 maps to 13q12-q13 and encodes a transcript of 10,157 bp. Other cancers that have been described in BRCA2 mutation carriers include those of the larynx. Human chromosome 13q has been shown previously by LOH studies to harbor several tumor suppressor genes for head and neck squamous cell carcinoma (HNSCCs). We therefore examined the role of BRCA2 in the development of these cancers. Only 6/22 (27%) of the laryngeal cancers we examined demonstrated LOH of the BRCA2-containing region. These and 10 other HNSCCs of different origins that were demonstrated by LOH studies to have lost the region of chromosome 13 containing BRCA2 were examined for alterations in this gene. SSCP analysis failed to reveal any alterations leading us to conclude that BRCA2 alterations are not frequently involved in the pathogenesis of HNSCCs and that the observed LOH of chromosome 13 loci is due to other, as yet, unidentified tumor suppressor gene(s). Interestingly tumors with LOH in this region (proximal to D13S118) were far more likely to be derived from women than men. This is unusual since HNSCCs are usually fourfold more common in men than in women.